In accumulators of the prior art an adjustment of the area in which the paper sheets are received to accommodate variable formats is possible only within relatively narrow limits and such adjustment requires complicated means. Furthermore, a reliable, trouble-free operation is not insured to the same degree throughout the range of different paper formats to which the accumulator can be adjusted. In addition, the area in which the paper sheets is received is constituted in accumulators of the prior art by a closed bottom of sheet metal, which sometimes exerts a suction effect on the paper sheet that has been received first so that the paper sheet may not be uniformly fed to the receiving area. Furthermore, the closed bottom of the trough which is provided in the receiving area promotes the build-up of an electrostatic charge which renders the feeding of the paper sheet more difficult. Moreover, in the known accumulators of the prior art in which the receiving area is constituted by a closed bottom, those parts of the equipment which are disposed beneath the bottom are accessible only with difficulty for repair and service work.
Accordingly, it is a primary object of the invention to provide an accumulator which
(a) allows access to those parts of the equipment which are disposed beneath the receiving area of the accumulator,
(b) avoids both a suction and an electrostatic attraction between the receiving surface of the accumulator and the paper sheet to be conveyed, and
(c) permits the surface of the receiving area to be adjusted in a simple manner in a direction parallel to the direction of travel of the paper to accommodate a variable paper format.